• Transactions of the Korean hydrogen and new energy society
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• v.35 no.1
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• pp.27-33
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• 2024

In this study, we researched Ni-based bead catalysts for the catalytic thermal decomposition of light hydrocarbons. A Ni-based bead-type catalyst was prepared, and catalytic thermal decomposition performance of light hydrocarbons was evaluated. The 30Ni/Al₂O₃ catalyst exhibited the most superior performance, with the presence of both fibrous and carbon black forms on the catalyst surface. Catalytic performance was evaluated for particles sized between 150-250 and 500 ㎛, with excellent catalytic thermal decomposition properties in the 150-250 ㎛ range. After the reaction, carbon removal through collision between catalysts in the fluidized bed was observed. It was confirmed that as the particle size increases, the amount of carbon removed increases.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1643-1646
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• 2012

Three Ni-based catalysts with different clay as support were prepared and tested in the hydrogenation of maleic anhydride, among which Ni/clay1 showed best activity and selectivity. Over Ni/clay1 catalyst prepared by impregnation method, 97.14% conversion of maleic anhydride and 99.55% selectivity to succinic anhydride were obtained at $180^{\circ}C$ under a pressure of 1 MPa. Catalytic activity was greatly influenced by the temperature and weighted hourly space velocity. Catalyst deactivation studies showed that this catalyst have a long life time, the yield of MA still higher than 90% even after a reaction time of 60 h. X-ray diffraction (XRD) and $H_2$ temperature programmed reduction (TPR) were use to investigate the properties of the catalyst. XRD and TPR studies showed that Ni was present as $Ni^{2+}$ on the support, which indicated that there was no elemental nickel ($Ni^0$) and $Ni_2O_3$ in the unreduced samples. The formation of Ni was strong impact on catalytic activity.

• Korean Chemical Engineering Research
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• v.52 no.5
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• pp.678-687
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• 2014

The catalytic performance of silicon carbide supported nickel catalysts modified with or without second metal (Co, Cu and Zn) for the methanation of CO has been investigated in a fixed-bed reactor using a feed consisting of 25% CO and 75% $H_2$ without any diluent gas. It has been found that the introduction of Co species can clearly improve the catalytic activity of Ni/SiC catalyst, whereas the addition of Cu or Zn can result in a significant decrease in the catalytic activity. The characterizations by means of XRD, TEM, XPS, CO-TPD and $H_2$-TPR indicate that the addition of Co could decrease the particle size of active metal, increase active sites on the surface of methanation catalyst, improve the chemisorption of CO and enhance the reducibility of methanation catalysts. Additionally, the special interaction between Co species and Ni species is likely favorable for the dissociation of adsorbed CO on the surface of catalyst, and this may also contribute to the high activity of 5Co-Ni/SiC catalyst for CO methanation reaction. For 5Cu-Ni/SiC catalyst and 5Zn-Ni/SiC catalyst, Cu and Zn species could cover partial nickel particles and decrease the chemisorption amount of CO. These could be responsible for the low methanation activity. In addition, a 150h stability test under 2 MPa and $300^{\circ}C$ showed that 5Co-Ni/SiC catalyst was very stable for CO methanation reaction.

• Transactions of the Korean hydrogen and new energy society
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• v.26 no.6
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• pp.507-515
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• 2015

HI decomposition reaction requires a catalyst for the efficient production of hydrogen as a key reaction for hydrogen production in sulfur-iodine thermochemical water-splitting (SI) cycle. As a catalyst used in the reaction, the performance of platinum catalyst is excellent. While, the platinum catalyst is not economical. Therefore, studies of a nickel catalyst that could replace platinum have been carried out. In this study, the characteristics of the catalytic HI decomposition on the amount of loaded nickel (Ni = 0.1, 0.5, 1, 3, 5, 10 wt%) were investigated. As the supported Ni amount increased up to 3 wt%, HI decomposition was found to increase in linear proportion. However, the conversion of $Ni/Al_2O_3$ catalyst loaded above 3 wt% was not linear. It was thought that the different HI decomposition characteristics was caused in the size and metal dispersion of Ni particles of catalyst. The physical property of catalyst before and after HI decomposition reaction was characterized by BET, chemisorption, XRD and SEM analysis.

• Applied Chemistry for Engineering
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• v.32 no.6
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• pp.627-631
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• 2021

Research on induction heating catalyst system was conducted to solve problems of the existing catalyst system for removing volatile organic compounds. In the present study, three types of Ni-based commercial catalysts were employed, and induction heating reaction characteristics including the catalyst volume, composition, heat treatment atmosphere, and position in the coil were investigated. The composition and volume of the catalyst affected the exothermic and toluene oxidation performance in the induction heating system. In particular, the Fe-added catalyst showed high exothermic performance compared to that of other catalysts consisting of more than 99% Ni, but had low toluene oxidation performance. In addition, the heat treatment in an air atmosphere of the Ni-based catalyst drastically reduced the performance. In the induction heating system, the optimal condition for the catalyst was to be located in the center of the coil. The catalyst showed similar activities among seven repeated experiments under the optimal condition derived from this work.

• Journal of Environmental Science International
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• v.22 no.8
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• pp.1019-1027
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• 2013

Sulfur hexa-fluoride has been used as a etching gas in semiconductor industry. From the globally environmental issues, it is urgent to control the emissions of this significant greenhouse gas. The main objective of this experimental investigation was to find the effective catalyst for $SF_6$ decomposition. The precursor catalyst of hexa-aluminate was prepared to investigate the catalytic activity and stability. The precursor catalyst of hexa-aluminate was modified with Ni to enhance the catalytic activities and stability. The catalytic activity for $SF_6$ decomposition increased by the addition of Ni and maximized at 6wt% addition of Ni. The addition of 6wt% Ni in precursor catalyst of hexa-aluminate improved the resistant to the HF and reduced the crystallization and phase transition of catalyst.

• Bulletin of the Korean Chemical Society
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• v.26 no.6
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• pp.887-891
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• 2005

Novel nickel catalyst deposited on nanoporous carbon was found to be an efficient catalyst for the epoxidation of simple alkenes with $O_2$ and isobutyraldehyde under mild conditions. Alkenes exhibited different reactivities towards Ni-catalyst and epoxidation with stilbene proceeds stereospecifically. This may be rationalized with the mechanism involving coordinated acylperoxy radical intermediate. Nickel contents depend on the preparative methods and the KNI-3 catalyst, which was synthesized by wet impregnation of $Ni(NO_3)_2$ into nanoporous carbon, shows the highest activity. The activity of the catalyst is well correlated with contents of nickel. Recycled catalysts suffer considerable loss of activity due to leaching of catalytic active species, nickel.

• Transactions of the Korean hydrogen and new energy society
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• v.14 no.1
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• pp.69-80
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• 2003

Nickel catalyst has been used for natural gas reforming with carbon dioxide, In this study, catalyst support used was HY zeolite. The optimum loading of Ni in the catalysts was 13 wt%. The effect of promoters, such as Mg, Mn, and K, was also studied. The addition of promoters to Ni catalyst improved the stability of catalysts and carbon deposition on Ni catalyst was suppressed. The reforming reactivity of promoter-added Ni catalyst was higher than that of Ni catalyst without any promoters. SEM, XRD, BET, TGA and FTIR tests were tried to characterize the catalyst structure before and after reaction.

• Journal of the Korean Ceramic Society
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• v.36 no.5
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• pp.504-512
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• 1999

The high-quality carbon nanofibers were prepared by chemical vapor deposition of gas mixtures of CO-H2 and C3H8-H2 over Fe-Cu and Ni-Cu bimetallic catalysts. The yield and structure of carbon nanofiber produced were altered by the change of catalyst composition and reaction temperature. The high yields were obtained around 500$^{\circ}C$ with e-Cu catalyst and around 700-750$^{\circ}C$ with Ni-Cu catalyst and the relatively higher yields were obtained with the bimetallic catalyst containing 50-90% of Ni and Fe respectively in comparison with the pure metals. The carbon nanofibers produced over the Fe-Cu catalyst at around 500$^{\circ}C$ with the maximum yields had the highest surface ares of 160-200 m2/g around 650$^{\circ}C$ which was slightly lower than the temperature for maximum yields. In order to examine the characteristics of carbon nanofibers as catalyst support Ni and Co metals were supporte on the carbon nanofibers and CO hydrogenation reaction was performed with the catalysts. The particle size distribution of Ni and Co supported over the carbon nanofibers were 6-15 nm and the CO hydrogenation reaction rate with the carbon-nanofiber supported catalysts was much higher than that over the other supports.

• Proceedings of the Korean Vacuum Society Conference
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• 2013.02a
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• pp.166-166
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• 2013

Mesoporous $SiO_2$-supported Ni catalysts (Ni/$SiO_2$ and Ni/$TiO_2$/$SiO_2$) were fabricated by atomic layer deposition (ALD), and their catalytic activity and stability were investigated in carbon dioxide reforming of methane (CRM) reaction at $800^{\circ}C$ The Ni/$SiO_2$ catalysts showed high stability as a result of confinement of Ni particles with a mean size of ~10 nm within the pores of $SiO_2$ support. Besides, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and transmission electron microscopy (TEM) results showed that the Ni nanoparticles were partially buried inside the $SiO_2$ support. The strong interaction between Ni and the $SiO_2$ support could also be advantageous for long-term stability of the catalyst. In case of the Ni/$TiO_2$/$SiO_2$ catalyst, it was found that the catalytic activity of 10 nm-sized Ni nanoparticles was not much influenced by $TiO_2$ addition.